Genetic hitchhiking, mitonuclear coadaptation, and the origins of mt DNA barcode gaps
Genetic hitchhiking, mitonuclear coadaptation, and the origins of mt DNA barcode gaps
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DOI：
10.1002/ece3.6640
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发表时间：
2020-08-03
影响因子：
2.6
通讯作者：
Hill, Geoffrey E.
中科院分区：
文献类型：
--
作者：
Hill, Geoffrey E.
基于线粒体(Mt)核苷酸序列的DNA条码是一个谜。Mt进化的中性模型预测，DNA条形码不适用于最近分化的分类群，然而，mt DNA条形码准确地界定了许多双边动物的物种。与此同时，对植物和真菌来说，mt DNA条形码经常失败。我认为，由于mt基因产物必须与核基因产物协同作用，所以mt基因组的进化最好是在充分考虑对mt基因施加选择压力的两个环境：外部环境和内部基因组环境的情况下才能理解。此外，至关重要的是，不仅要充分考虑mt基因蛋白产物的适应性进化，而且还要考虑mt转移RNA和mt核糖体RNA的适应性进化。Mt基因组上不参与重组的基因的紧密连锁可以促进对mt基因组中的任何元素进行正选择时的选择性扫描，导致群体内mt遗传多样性的清除和新mt DNA序列的快速固定。因此，决定mt DNA序列是否诊断物种边界的最重要因素可能是mt染色体参与重组的程度。
DNA barcoding based on mitochondrial (mt) nucleotide sequences is an enigma. Neutral models of mt evolution predict DNA barcoding cannot work for recently diverged taxa, and yet, mt DNA barcoding accurately delimits species for many bilaterian animals. Meanwhile, mt DNA barcoding often fails for plants and fungi. I propose that because mt gene products must cofunction with nuclear gene products, the evolution of mt genomes is best understood with full consideration of the two environments that impose selective pressure on mt genes: the external environment and the internal genomic environment. Moreover, it is critical to fully consider the potential for adaptive evolution of not just protein products of mt genes but also of mt transfer RNAs and mt ribosomal RNAs. The tight linkage of genes on mt genomes that do not engage in recombination could facilitate selective sweeps whenever there is positive selection on any element in the mt genome, leading to the purging of mt genetic diversity within a population and to the rapid fixation of novel mt DNA sequences. Accordingly, the most important factor determining whether or not mt DNA sequences diagnose species boundaries may be the extent to which the mt chromosomes engage in recombination.